FMRI OF NORMAL LANGUAGE DEVELOPMENT IN CHILDREN

几十年来，人们一直使用行为方法研究人类语言发展，但这一重大童年成就的神经生物学基础还没有被很好地理解。绘制语言在整个正常发育过程中在大脑中的功能分布图，可以提供对正常语言习得和干扰儿童群体语言障碍的性质的相当大的洞察力。在临床上，语言是发育性或获得性儿童神经疾病最早的标志物之一。在儿童中，对语言功能障碍的评估还必须考虑到可能存在的正常发育变化。功能磁共振成像(FMRI)为语言发展研究提供了一种非侵入性技术。虽然功能磁共振成像已经被用来检查成人的语言和语言病理，但这项技术在儿童中的应用一直受到限制。这在一定程度上是由于fMRI固有的低信噪比和对运动的敏感性。然而，使用3Tesla核磁共振扫描仪和经验丰富的儿科神经成像团队，我们能够常规地获得低至5岁儿童的高质量fMRI语言地图。我们计划在3特斯拉使用功能磁共振成像技术来描绘5到18岁儿童正常语言发展的具体方面。我们将检查四项旨在跨越语言发展进程的语言任务：其中两项挖掘在学龄前几年获得的技能，另两项挖掘持续发展到学龄前的技能。这些技能领域的标准语言地图将从5岁到18岁(N=280名正常受试者)每个年龄段的10名男孩和10名女孩的复合fMRI数据构建。这些地图的差异将被考虑与受试者的年龄和语言技能水平(通过标准化测试来衡量)有关。最后，将通过将正常语言数据与20名因围产期大脑中动脉中风而导致语言能力受损的患者的数据进行比较，来评估正常语言数据的实用性。该项目将为语言的功能磁共振研究建立标准数据，以作为儿童广泛神经障碍研究的参考。

Human language development has been studied using behavioral methods for decades, yet the neurobiologic basis of this major childhood accomplishment is not well understood. Mapping the functional distribution of language in the brain throughout normal development could provide considerable insight into the nature of both normal language acquisition and disorders that disrupt language in pediatric populations. Clinically, language is one of the earliest markers for developmental or acquired pediatric neurologic disorders. In children, assessment of language dysfunction must also take into account normal developmental changes that may exist. Functional magnetic resonance imaging (fMRI) offers a noninvasive technique which could be applied to the study of language development. Whereas fMRI has been used to examine language and language pathology in adults, applications of this technology in children have been limited. This is due in part to the inherently low signal-to- noise ratio and sensitivity to motion of fMRI. However, with the use of a 3 Tesla MRI scanner and an experienced pediatric neuroimaging team, we are able to routinely obtain high quality fMRI language maps in children as young as five years of age. We propose to use fMRI techniques at 3 Tesla to map specific aspects of normal language development in children from ages 5 to 18. We will examine four language tasks designed to span the progression of language development: two of which tap skills acquired during the preschool years and two of which tap skills that continue to develop into the school years. Normative language maps for each of these skill domains will be constructed from composite fMRI data from 10 boys and 10 girls at each year of age from 5 through 18 (N=280 normal subjects). Variations in these maps will be considered relative to both subject age and level of language skill (as measured by standardized testing). Finally, the utility of the normal language data will be evaluated by comparing it against data obtained from a group of 20 patients with impaired language ability resulting from perinatal stroke in the middle cerebral artery. This project will establish normative data for fMRI studies of language to be used as a reference in studies of a wide range of neurologic disorders in children.